In Hinduism and Buddhism, a klesha is a negative mental state that clouds the mind causing suffering and the conditions for suffering to arise. Klesha means “poison” in Sanskrit. Kleshas also refer to the obstacles that prevent a person from reaching a state of enlightenment and freedom from samsara.
Patanjali’s Yoga Sutras describe kleshas as impediments to spiritual growth. Yogic practices such as meditation and pranayama breathing exercises provide methods to overcome kleshas.